<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>第一堂课</title>
    <link rel="stylesheet" href="style.css">
    <style>
        .color {
            width: 360px;
            height: 36px;
            background-color: blue;
            color: white;
            line-height: 36px;
            text-indent: 2em;
        }

        .color1 {
            text-align: center;
        }
    </style>
</head>

<body>
    <div class="">hello world!</div>
    <div class="">hello 小王！</div>
    <div class="">hello 小段</div>
    <div class="">hello 小段</div>
    <div class=""></div>
    <div id="dd"></div>
    <div class="header">这是头部</div>
    <p class="color">公使馆你难道</p>
    <p class="color color1">公使馆你难道</p>
</body>

</html>